TPS Throttle Position Sensor Bottom Screw Stripped, 87 Turbo Automatic Unmodified

bestsupraever

New Member
Nov 14, 2015
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Florida
Hi Guys, hope someone has a miracle idea, although I probably know the answer to this problem already.
I finally got around to checking the timing and tps of my 87 Turbo,Automatic that I got in Oct. I felt the idle was not quite right, it seems a bit low (about 550 in park), and a bit lumpy at times, mostly when fully warmed up. throttle response seems good, no lag, backfiring, or jumping around. The timing is spot on, but the tps as I suspected is not. It measures 6.15 ohms (20k scale),with the 0.9mm feeler gauge in place. I understand it should be infinity. So I set about to adjust it. Now here's the problem, The bottom screw is worn stripped, (honest guys it wasn't me), I am able to get an offset phillips head in there, but not enough leverage to turn it, it is only chewing it up more than it was. I was able to get a mirror in there and see that it is pretty badly stripped. If it wasn't already stripped, the offset phillips would have worked fine. So I fiqured I would take it to the toyota dealer. They checked it out, and confirmed that it was out of adjustment, and also that the throttle body is clean inside, as someone cleaned it before I had it. They also verified the timing was good. But they said they could not get the screw loose without taking the whole intake manifold off, a big money job. So I left there as I felt there must be a less involved way to do it.
So do any of you guys know of a better way to get the bottom screw loose. Special tool, extractor, etc. without taking the intake manifold off.
I thought about a small ratchet with a screw extractor or phillips bit, but don't know if I can get enough force on it to not strip the screw worse, or trying to unbolt the ISC and moving it just enough out of the way to get an extension with a screw extractor tip in there, or an impact driver in there. or at very last ditch effort, taking the top screw off and just breaking it out of there, once removed, I can just remove the bottom screw with a pliers. And get a new tps to put back in with hex head bolts.
Thanks for any ideas.--Semper Fi
 

bestsupraever

New Member
Nov 14, 2015
42
0
0
Florida
Hi Guys, ok I finally got the bottom screw out. I super glued a #2 1" long phillips bit to it. after about 2 hours it was set very strong. I was then able to turn it with a small 1/4" wrench. got the screw out with the bit still glued to it. needless to say that screw won't be going back in. I will get a few hex head screws to replace it with.
So here is another question that is a mystery. I have a 1987 supra service manual. In the 87 manual where it explains which pins are idl and e2 the diagram shows the same location,(e2 on top, and idl second pin down), on both the ge and the gte engines. yet they are the same part #. But when looking at the TSRM online ,http://www.cygnusx1.net/Supra/Librar...spx?S=FI&P=101 it clearly shows the pins in the opposite ends of the connector for the 2 engines. Now this makes sense to me as the TPS is installed in opposite directions on the 7mge,(facing drivers fender)as compared to the 7mgte tps ( facing passenger side fender), so the pins should be opposite positioned when installed, provided each engine gets the same part # which they do. So does anyone for sure which pins are the idl and e2 when installed on the 7mgte engine. I am thinking that the TSRM online is the correct configuration, and the 87 manual was incorrect, because there was a TSB on setting the TPS published in Aug 1989. Unfortunately I don't have access to that TSB.
Thanks--Semper Fi
 

bestsupraever

New Member
Nov 14, 2015
42
0
0
Florida
Hi guys, I attempted to adjust the tps last night, since I got the bottom screw out finally. I wasn.t able to get the settings close enough to the TSRM instructions. I also tried the 87 manual instructions, but I now know that manual is in error, so I followed the TSRM. I finally determined the tps to be to far out of spec to use. No codes were ever thrown about the tps, but it was not accurate enough just th same. So I ordered a new toyota oem unit from amazon. It was a few cents over 100.00 plus shipping and tax. Shipping would have been free, but I chose the overnight for 7.00 because I wanted to get it done today, and even with the extra shipping cost, it was still less expensive that my local dealer, who couldn't get it for me until tomorrow anyway. The part was waiting for me at my door this morning around 8 am. I installed it this afternoon using the tsrm for a guide. It went right in and set just as it was supposed to. All the readings are right in the middle of the ranges, and the infinity setting is right on. I just came back from a test drive. Took it out for about 2 hours. Fast slow, stopped a few times and started again in about 15 minutes. Highway and urban. It idles right on the money now right around 650. Smooth no hiccups, starts right up, hot and cold, great throttle response, even the trans feels like it is shifting in a better range. Definitely worth doing, and the TSRM is definitely correct as opposed to my 87 manual, even on my 87 gte.
Luck to All. Semper Fi